# [a] -> (a -> Bool) -> [a]

dropWhile p xs returns the suffix remaining after takeWhile p xs: > dropWhile (< 3) [1,2,3,4,5,1,2,3] == [3,4,5,1,2,3] > dropWhile (< 9) [1,2,3] == [] > dropWhile (< 0) [1,2,3] == [1,2,3]
filter, applied to a predicate and a list, returns the list of those elements that satisfy the predicate; i.e., > filter p xs = [ x | x <- xs, p x]
takeWhile, applied to a predicate p and a list xs, returns the longest prefix (possibly empty) of xs of elements that satisfy p: > takeWhile (< 3) [1,2,3,4,1,2,3,4] == [1,2] > takeWhile (< 9) [1,2,3] == [1,2,3] > takeWhile (< 0) [1,2,3] == []
Direct MonadPlus equivalent of filter filter = (mfilter:: (a -> Bool) -> [a] -> [a] applicable to any MonadPlus, for example mfilter odd (Just 1) == Just 1 mfilter odd (Just 2) == Nothing
The findIndices function extends findIndex, by returning the indices of all elements satisfying the predicate, in ascending order.
Deprecated: use escapeURIString, and note the flipped arguments
Can be used to make a string valid for use in a URI.
The sortWith function sorts a list of elements using the user supplied function to project something out of each element
map f xs is the list obtained by applying f to each element of xs, i.e., > map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn] > map f [x1, x2, ...] == [f x1, f x2, ...]
iterate f x returns an infinite list of repeated applications of f to x: > iterate f x == [x, f x, f (f x), ...]
Applied to a predicate and a list, all determines if all elements of the list satisfy the predicate. For the result to be True, the list must be finite; False, however, results from a False value for the predicate applied to an element at a finite index of a finite or infinite list.
Applied to a predicate and a list, any determines if any element of the list satisfies the predicate. For the result to be False, the list must be finite; True, however, results from a True value for the predicate applied to an element at a finite index of a finite or infinite list.
Escape character if supplied predicate is not satisfied, otherwise return character as singleton string.
The groupWith function uses the user supplied function which projects an element out of every list element in order to to first sort the input list and then to form groups by equality on these projected elements
A combination of parList and map, encapsulating a common pattern: > parMap strat f = withStrategy (parList strat) . map f
Lift a function to actions. This function may be used as a value for fmap in a Functor instance.
This function may be used as a value for fmap in a Functor instance.
until p f yields the result of applying f until p holds.
Apply a transformation everywhere in bottom-up manner
Apply a transformation everywhere in top-down manner